This invention relates to a drive mechanism for a filter assembly. More particularly, this invention relates to a drive mechanism for a tilting pan filter assembly. This invention also relates to an associated method for operating a filter assembly.
Tilting pan filter assemblies are well known in the art. These filter assemblies each have a plurality of radially oriented pans which are rotated about a common vertical axis on a carriage or turntable rack. In some instances, a link chain is coupled around the outer periphery of the rack for meshing with a plurality of independently mounted sprockets outside the filter which are driven by electric motors. More frequently, the carrier rack is rotated about the vertical axis by a single electric motor which is operatively connected to a ring or bull gear on the rack via a transmission assembly.
These conventional single-point electric drives have numerous disadvantages. The requisite shear pins, high-torque long-delivery gear reducers, and sensitive electric control systems are susceptible to corrosion, wear, and unreliability owing to harsh conditions frequently encountered at remote plant sites. Maintenance operations are, therefore, difficult and frequent. Many centering casters are necessary.
Most of these disadvantages also pertain where a single hydraulic motor is used to drive a rotating filter. Because such filters are so large, the gear boxes required are huge.